title: Assay of melanotropic peptides in an in vitro mammalian system.
abstract: A reproducible and sensitive assay for melanotropic agents is described employing mouse melanoma cells in culture and measuring tyrosinase activity in terms of production of tritiated water from L-(ring-3,5-3H)-tyrosine. Molar concentrations of peptides inducing one-half maximal stimulation of tyrosinase activity were: beta-MSH, 1 +/- 2 x 10(-9); alpha-MSH and Beta h-LPH, 1 +/- 2 x 10(-8); ACTHp, 1 +/- 2 x 10(-7). Beta p 9-18-MSH and melanotropin potentiating factor, beta s 88-91-LPH exhibited no activity at concentrations as high as 10(-5)M.
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D002478:Cells, Cultured; D066298:In Vitro Techniques; D009074:Melanocyte-Stimulating Hormones / Q000032:analysis*; D008545:Melanoma / Q000201:enzymology / Q000503:physiopathology*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000032:analysis; D009374:Neoplasms, Experimental / Q000201:enzymology / Q000503:physiopathology; D012878:Skin Neoplasms / Q000201:enzymology / Q000503:physiopathology*
chemical_list: D009074:Melanocyte-Stimulating Hormones; D014442:Monophenol Monooxygenase